In recent years, sintered ceramic sheets have become widely used in electronic appliances such as cell phones and personal computers due to their superior properties. Such cut-out sintered ceramic sheets can be processed into various shapes to make further use of their superior properties.
One known shape-processing method for a sintered ceramic sheet includes processing the sheet into a desired shape at the ceramic green sheet stage. A sintered ceramic sheet obtained by this method produces a processed shape based on a shrinkage factor of the ceramic green sheet expected during the course of sintering. Typically, as shown in FIG. 11, when a ceramic green sheet 11 is sintered, the sintered ceramic sheet 12 shrinks be about 20%. One problem is that a difference can occur between the designed size calculated included the shrinkage factor, and the actual size of the sintered ceramic sheet obtained.
One solution to this problem is thus to process the sintered ceramic sheet after sintering. For example, Japanese Patent Application Publication No. 2002-359317 discloses procedures to obtain a cut-out sintered ceramic sheet of desired dimensions by performing a laser process and a dicing process on the sintered ceramic sheet.
A disadvantage of dicing is that dicing requires that the rotary knife directly contact the sintered ceramic sheet during cutting, making it impossible to process the sintered ceramic sheet into complex shapes. A disadvantage of laser processing is that heat is generated at the point of the laser focus, which can change the properties of the cut-out sintered ceramic sheet. Further, since longer time is required to process a complex shape, production efficiency decreases, and processing costs increase.
To overcome the disadvantages of the prior art processes, the present invention provides a procedure by which a sintered ceramic sheet can be processed quickly into a complex shape, and a cut-out sintered ceramic sheet can be obtained with very high dimensional accuracy.